Robot Krabs is the robot version of Mr. Krabs in the episodes Imitation Krabs, New Leaf, and Spy Buddies. In the episode Imitation Krabs, Plankton makes a robot that looks similar to Mr. Krabs. It was accidentally destroyed by SpongeBob when he put a Penny into the Self-Destruct Coin Slot 1 Cent, causing the Robot and the Chum Bucket itself to become destroyed.
Robot Krabs is a highly sophisticated robot that has many different features. Inside, from where Plankton controls it, there are hundreds of levers and pulleys to make the robot do many things. The robot is red and constructed from metal, with a metal suit as stated by SpongeBob. It has the big eyes and its face acts and looks like a microphone. the robot appears to wear the same clothing as Mr. Krabs, but made from metal.
The robot has a self-destruct device activated by a penny inserted through a coin slot on his belt buckle and he can disguise himself as a bread toaster.
One of the giveaways that the robot is not Mr. Krabs is that it periodically emits an exhaust fume with an audible noise from an exhaust pipe at the rear whenever it lies.
Operation: Krabby Patty
In the video game Operation Krabby Patty, Plankton uses Robot Krabs to steal Krabby Patties. However, this robot is designed more different. It is rusty, has no shirt or pants design, has more crooked arms, uses wheels for legs, and the chest somewhat resembles Mechagodzilla's.
It is unknown how in New Leaf, there was the robot in the Krusty Krab closet filled with Plankton's failures since the robot from Imitation Krabs blew up. There are three logical explanation to how that could happen:
New Leaf happened after Spy Buddies.
There was another attempt before New Leaf in which one of the robot's design survived after Plankton's unseen plan was foiled.